Photosynthetic pigments content and parameters of oxidative stress in the amaranth species with increasing water deficiency

The dynamics of the photosynthetic pigments content and parameters of oxidative stress with an increasing water deficit in the leaves of 40-days-old plants of two amaranth species - Amaranthus paniculatus L. (cv. Rubin) and Amaranthus caudatus L. (cv. Chyrvony aksamit), grown in a pot culture, was studied. Specific features of the development of water deficiency in amaranth leaves were revealed: amaranth plants Amaranthus paniculatus L. showed a stronger development of water deficit in leaves than Amaranthus caudatus L. after 4-days soil drought, which after 8 days increased in two species to 73.7 and 55.7 %, respectively. Under moderate drought, the amount of photosynthetic pigments (chlorophyll (Chl) and carotenoids) based on dry leaf weight increased in two amaranth species, but after 8 days of soil drought, the content of Chl (a + b) was reduced by 2.0-2.1 times, and carotenoids - 1.8-1.9 times relative to the physiological level. As a result of a 4-days soil drought in the leaves of Amaranthus paniculatus L., there was a significant decrease in the content of reactive oxygen species (ROS) and the activity of lipid peroxidation (LPO), while in Amaranthus caudatus L. an increase in the levels of ROS and LPO was observed. With an increase in the pressure of the stress factor in the leaves of amaranth of the two studied species, a decrease in the ROS content and LPO activity relative to physiological values was revealed. A conclusion was made about the different mechanisms of ROS generation and the flow of LPO processes at different stages of soil drought in the leaves of different amaranth species.

THE EFFECT OF GROWING CONDITIONS ON THE QUALITATIVE AND QUANTITATIVE INDICATORS OF CHLORELLA VULGARIS

The complex effect of two factors (the optimum ratio of nutrients of the medium and the electrostatic field) on the qualitative and quantitative indicators of Chlorella vulgaris was investigated. It is shown that the use of a medium with optimal concentrations of mineral substances and an electrostatic field with a voltage of 15 kV and an exposure time of 72 hours has a positive effect on growth rates, the size of microalgae cells and their viability, contributes to obtaining a culture with a density of 50 mln cells / ml 18 hours faster in comparison with the cultivation of generally accepted methods. It has been established that when two factors are influences on the cells of the Chlorella a mutagenic effect is not observed. Analysis of the microalgae culture grown under the influence of the studied factors showed that its chemical composition was consistent and with several indicators exceeded that of chlorella cultivation according to classical technologies. It was revealed that the activity of catalase and superoxide dismutase of microalgae grown in optimal conditions of the nutrient medium and the electrostatic field, significantly exceeded similar values of Chlorella vulgaris, which was not subjected to electrostatic stimulation. The high activity of the studied enzymes in Chlorella cells is shown in comparison with higher plants – components of bio-antioxidant preparations, such as Amaranthus paniculatus L. and Nicotiana tabacum L. According to the results of the toxicological study the absence of the content in Chlorella of the main poisonous substances for body animals and humans (mercury, arsenic) has been established. As a result of the research, it was proposed to use the established optimal parameters of both factors in the cultivation of C. vulgaris.

Биологические особенности амаранта в условиях Кабардино-Балкарии

Амарант — однолетнее травянистое растение, по химическому составу относится к числу наиболее ценных растений, отличается высоким и сбалансированным содержанием белка, макро- и микроэлементов, масла, пектина. Проведен сравнительный анализ биологических показателей интродуцированных форм и гибридов амаранта в условиях предгорной и степной зон Кабардино-Балкарии (КБР) для выявления наиболее перспективных образцов с высоким и стабильным урожаем семян и зелёной массы. Исследована мезоструктура листьев, их пигментный состав, флоуресценция хлорофилла и интенсивность фотосинтеза у различных образцов амаранта, выращенных в искусственных условиях. Установлено, что внесение в почву минеральных удобрений формирует и обеспечивает максимально комфортные и благоприятные условия для формирования мощной листовой поверхности и повышения доли листьев в массе надземной части растений амаранта, что улучшает кормовые достоинства данной культуры. Для целей кормопроизводства в условиях КБР рекомендуется выращивать Amaranthus cruentus L., Amaranthus caudatus L., Amaranthus hybridus L., Amaranthus paniculatus L. Для обеспечения высокого, более 1000 ц/га урожая зеленой массы, посевы необходимо создавать с размещением растений 40 × 15 см, а для высокой семенной продуктивности — 70 × 35 см при внесении в почву минеральных удобрений N90P90K90.

Investigation of Nanohydrophobic Sand as an Insulating Layer for Cultivation of Plants in Soils Contaminated with Heavy Metals

The paper presents the results of laboratory experiments to test hydrophobic sand, on the basis of soot as an insulating for growing plants-hyperaccumulators heavy metals ? amaranth (Amaranthus paniculatus) and sunflower (Helianthus annuus) plants. For the first time in agriculture hydrophobic sand was used for the irrigation of water-saving experiments for growing palms in arid areas of the UAE. The hydrophobic sand was obtained from normal beach sand, which is covered by small particles of pure silica, pretreated pairs trimethylhydroxysilane, (CH3)3SiOH. After this treatment, the outer shell grains saturated groups of compounds insoluble in water, sand and exposes hydrophobic properties. Thus obtained nanohydrophobic sand is considered to be physiologically safe for plants and supplied by the manufacturer with 30-year warranty of the hydrophobic effect. In our experiments we used the conventional washed river sand, as adhesive bases used polyurethane glue SD-600 is dissolved in ethyl acetate. The sand thus obtained is added 1% superhydrophobic soot. The sand is obtained by using carbon black becomes hydrophobic properties, does not transmit moisture, it has virtually no adverse effect on plant growth. To test hydrophobic sand used plastic pots (volume 1 l). The lower layer of the moistened soil-ground containing various concentrations of heavy metals (TM), the next separation layer ? nanohydrophobic sand, and the top layer ? a layer of fertile soil enriched vermicompost for growing plants. When watering plants nanohydrophobic sand layer retains water and prevents migration of TM (Zn, Cd, Cu) of the lower contaminated layer to the upper, the mold.